1. Field of the Invention
The present invention is directed to a swivel joint assembly for joining a pair of pipes together while allowing movement of the pipes with respect to each other. In particular, the present invention is directed to a pipe swivel joint assembly that will seal both internally and externally of the joint assembly.
2. Prior Art
Bulk liquid products, such as petroleum products, are often stored in large cylindrical storage tanks. Different types of roof structures are provided for the storage tanks. In one arrangement, a roof is supported and floats on the surface of the liquid product contained within the tank. The roof rises and falls as the level of fluid within the tank rises or falls. The floating roof is advantageous in that it minimizes product loss to the atmosphere. Floating roofs include pan-type, pontoon-type and double deck-type roofs. The roof and accompanying accessories are allowed to float from the lowest level to the maximum design liquid level and then return.
The roof and supporting structures must be designed to support specified loading conditions. The weight of rainfall on the roof is one such condition. Indeed, American National Standards Institute/American Petroleum Institute (ANSI/API) Standard 650 addresses these issues. For example, the roof must be designed to support minimum loads per square foot.
Floating roofs will often be provided with roof drains. Each roof drain will include a water sump to collect water on the top of the roof. In a typical design, the roof sump will be connected to a jointed series of pipe lengths which pass through the interior of the tank and then through the base or sidewall of the tank. Accordingly, water or other liquids gathering on the top of the roof will be drawn off through the drain system. The pipe lengths and joints will be submerged in the liquid product in the tank. The pipes and the swivel joints will, thus, be subject to liquid both within the joints from the roof drainage and on the exterior from the liquid product in the tank.
Drains will be designed to prevent the roof from accumulating a water level greater than design at a maximum rainfall rate.
In the past, swivel joints have been constructed which utilize a plurality of ball bearings to facilitate movement of one member with the other.
There remains a need for a swivel joint that will require minimum assembly and that may be serviced easily.
It is, therefore, a principal object and purpose of the present invention to provide a moveable swivel joint assembly for joining a pair of pipes.
It is a further object and purpose of the invention to provide a swivel joint assembly for joining a pair of pipes which includes: a male body member having a first end attachable to one pipe and a second end having external threads with a recess on each side of the external threads; a female body member having a first end attachable to the other pipe and a second end having internal threads mates with the male body member external threads; and wherein one o-ring seal resides in each recess to provide an external and internal seal for the swivel joint assembly.
It is a further object and purpose of the present invention to provide a moveable swivel joint assembly including a shoulder extending radially from the male body member and a cushioning spacer o-ring juxtaposed between the female body member second end and the shoulder.
It is a further object and purpose of the present invention to provide a moveable swivel joint assembly wherein the male body member first end terminates in a flange connectable to one pipe and wherein the female body member first end terminates in a flange connectable to the other pipe.
It is a further object and purpose of the present invention to provide a moveable swivel joint assembly for a floating tank roof wherein at least one joint assembly joins at least one pair of pipes.